Dishwasher ventilating system



March 31, 1964 T. w. DUNCAN 3,126,398

- DISHWASHER VENTILATING SYSTEM Filed Dec. 24, 1962 2 Sheets-Sheet 1 g} l 1 A INVENTOR THOMAS W. DUNCAN,

BY v 9 Fodw,

ATTORNEYS.

March 31, 1964 w, UN 3,126,898

DISHWASHER VENTILATING SYSTEM 2 Sheets-Sheet 2 Filed Dec. 24, 1962 R, mm mmMF 3 m 08 WW 01 TM ATTORNEYS United States Patent 3,126,898 DISHWASHER VENTILATHNG SYSTEM Thomas W. Duncan, Connersville, Ind, assignor to Design and Manufacturing Corporation, Connersviile, End, a corporation of Indiana Fiied Dec. 24, 1962, Ser. No. 246,324 11 Claims. (Cl. 134-99) The invention relates to a dishwasher ventilating system, and more particularly to a ventilating system for multiple cycle dishwashers. Dishwashers of this type are generally provided with automatic means for shifting from washing to rinsing to drying cycles in various sequences.

Heretofore, the drying cycle of an automatic dishwasher has presented the problem of introducing fresh air into the tableware containing vat, while at the same time disposing of the steam and moisture laden air remaining in the vat from the washing and rinsing cycles. One of the earliest solutions to this problem was to provide automatic means for partially opening the machine door after the rinsing cycle. This resulted in the discharge of a large quantity of steam and moisture laden air directly into the surrounding atmosphere of the room in which the dish-washing machine was located. The exhausted moisture had a tendency to condense on surfaces of the machine, as well as on walls and other surfaces within the room.

A number of ventilating systems for automatic dishwashing machines have been developed to obviate this problem. However, in general, these ventilating systems involved the fabrication of complex conduits, bafiies and condensation collectors.

It is therefore an object of the present invention to provide a ventilating system for an automatic dishwasher which is simple in construction and inexpensive to incorporate in the machine.

it is an object of the invention to provide means for introducing fresh air into the dishwasher vat during the drying cycle, while removing moisture laden air therefrom.

It is an object of the present invention to provide a system which will exhaust moisture laden air from the vat or tub without causing condensation on exposed surfaces of the machine, and without discharging steam and moisture laden air into the surrounding atmosphere under conditions productive of visible clouds of condensed vapor.

It is an object of the present invention to provide a system for introducing fresh air into the dishwasher vat and exhausting moisture laden air therefrom, inclusive of means for protecting interior mechanical parts and electrical controls of the machine from condensation and resultant damage.

It is an object of the invention to provide a ventilating system which will cause tableware within the vat to dry more rapidly than heretofore possible.

These and other objects of the invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, are accomplished by that structure and arrangement of parts of which certain exemplary embodiments will now be described. Reference is made to the accompanying drawings wherein:

FIG. 1 is a fragmentary front elevation, with parts in cross section, of an automatic dishwashing machine incorporating one embodiment of the present invention.

FIG. 2 is a fragmentary cross section of the automatic dishwashing machine of FIG. 1, taken at a right angle to the plane of the section in FIG. 1.

FIG. 3 is a vertical cross section of an automatic dishwashing machine incorporating a second embodiment of the present invention.

ICC

FIG. 4 is a fragmentary cross section of the dishwashing machine of FIG. 3, taken along the section line 44 of that figure.

It will be understood by one skilled in the art, that the ventilating system of the present invention may be incorporated in automatic dishwashing machines of either the front loading or top loading type. For purposes of an exemplary showing, FIGS. 1 through 4 illustrate embodiments of the invention as applied to front loading automatic dishwashing machines. The skilled worker in the art will understand from the disclosures herein how the principles of the invention may be applied to top loading machines.

Referring now to FIGS. 1 and 2, an automatic dishwashing machine is generally indicated at 1. It has an exterior casing with vertical walls 2, a top member 3 and a bottom member 5. The front wall of the machine is provided with the usual downwardly opening door 6. In some structures the door will have an enlarged port-ion 7 at its upper end. Electrical control elements including timers, and operating elements such as valves, (not shown) will be suitably located in or on the dishwashing machine as is conventional in the art.

Within the casing there is a tub or vat having side walls 8 and a bottom configured to provide a sump 9 of sufiicient depth to contain the water used to form a washing solution during the washing portion of the cycle and also the water used during the rinsing portion or portions of the cycle. There will he means (not shown) for the introduction and withdrawal of water or solutions, as is conventional in this art.

As is also conventional, means will be provided for causing water or solutions within the vat to impinge upon dishes and tableware held in conventional rack structures within the vat. VJhile other means may be employed, one such means is a conventional impeller shown at it) in FIG. 1 and driven by a motor 11 located beneath the sump 9'. In some structures the motor also operates a pump 12 which may be employed to agitate liquids within the vat, or to feed spray tubes or the like, or to withdraw fluids from the vat. In a front loading machine as illustrated, the door 6 forms an interruption in the front wall of the vat; but the arrangement is such, as well known in the art, that liquids thrown against the door will drain down into the sump. It will be usual to provide the vat of a front opening machine with a permanent top member 13. In top loading machines the vertical walls of the vat will be continuous, and the vat cover will be provided in connection with a top opening door, as is also well known.

In the practice of this invention the vat, adjacent the sump, will be provided with a downtake for air or moisture laden gases at a position somewhat above but adjacent the sump 9. The downtake will be shielded, as hereinafter more fully described, so that liquids thrown about within the vat will not enter it. The motor is provided with vanes 14 on its armature for the purpose of interior cooling of the motor parts; and the motor will have a housing 15 with a series of perforations 16 about its upper periphery to permit the escape of air drawn through the housing by the vanes 14.

In the practice of the invention the forced movement of air through the motor housing 15 is made use of to exhaust steam and moisture laden air from the vat during the drying portion or portions of the cycle of the'rna'chine. The downtake is illustrated in FIGS. 1 and 2 as a short section of metallic conduit 17 passing through a wall portion of the vat near the sump and arranged to be mounted fixedly on the vat as a permanent part thereof. There is a flanged shield 18 extending over the open end of the conduit 17 within the vat and acting to prevent the splash- 3 ing of liquids into the conduit while permitting the entry of gas.

In the embodiment shown in FIGS. 1 and 2 the motor housing element 15 lies above the bottom 5 of the dishwasher casing. This is readily possible because the motor 11 is normally mounted through the pump 12 to the sump 9 and is supported thereby. Metal parts are arranged to form a conduit 19 which utilizes a portion of the casing bottom 5 as one of its walls. At one end the conduit 19 is connected with the bottom portion of the motor housing 15, preferably in a gas tight way. Sealing means may be used if desired as indicated at 20. At its other end the conduit 19 has an upwardly extending tubular portion 21 which is connected with the downtake 17 by a conduit element 22. This last mentioned element, instead of being made of metal, may be made of impregnated paper or other rigid substance or of plastic or a rubbery substance combining flexibility with elasticity, so that the element 22 may be easily demounted for cleaning or other purposes, and so that when in place it wil malre tight connections with elements 17 and 2.1.

It will be evident that, due to the action of the vanes 14, gases will be withdrawn from the vat of the dishwasher through the downtake 17, and will pass through conduits 22 and 19 and through the motor housing 15, being expelled into the lower portion of the casing of the dishwashing machine through the perforations 16 in the motor housing 15. Because these gases will consist for the most part of air highly charged with moisture or of steam, it is well to dilute them with the surrounding atmosphere within the dishwasher casing to prevent condensation and the formation of visible clouds of condensed moisture. To this end the conduit 19 may be provided with a series of openings or louvers 23 in its upper portion or elsewhere, which louvers will permit the entrance of air as indicated by the arrows in FIG. 1. Also a series of perforations 24 may be formed in the lower part of the motor housing to permit the entrance of additional air.

Since gases will be continuously withdrawn from the vat during the operation of the motor, it will be clear that the vat should be provided with some means for the entrance of air. Such means may take any form desired, and may include any type of opening into the vat above the sump, the said opening or openings being provided with a splash guard. However, in top opening machines provision may be made for the entry of air in the vat around a top opening door or portion thereof. In a front loading dishwasher, the door will have the conventional hinging elements (not shown) at the ends of its bottom edge, but along the bottom edge there will be baflie means 25 coacting with an upstanding edge 26 of the vat. These elements will not be in contact so that there will be opportunity for the entrance of air into the vat along the bottom edge of the door as indicated by arrows in FIG. 2. It is conventional to provide the door of a front loading dishwasher with sealing means about its top and side edges.

It may be pointed out that some dishwashing machines have a trapped opening through a side wall of the vat for the introduction of water. Such an opening permits entry of air into the vat excepting when closed by the water trap action during the washing cycle.

The action of the vanes 14 on the motor and the conduit means heretofore described will be to maintain the vat itself under slightly less than atmospheric pressure. Consequently the draft will be inwardly as respects any openings through which the vat communicates with the outer air. This minimizes or prevents the escape of steam or moisture laden air from the vat directly into the room in which the dishwasher is located. Steam and moisture laden air will be withdrawn from the vat through the downtake 17 as heretofore explained, during all portions of the cycle or operation of the dishwashing machine; but the gaseous elements so withdrawn will be mixed with drier gases before being allowed to escape into the atmosphere so that undue condensation of moisture is avoided. That portion of the interior of the dishwasher casing 1 which underlies the vat 9 will preferably be in free communication with the ambient atmosphere. This may be accomplished by omitting a lower rear portion of the casing, or openings may be provided elsewhere as for example at points A and B as illustrated in FIG. 2.

Referring now to FIGS. 3 and 4, wherein like parts have been given like index numerals, a modification of the invention is shown as applied to a front loading dishwasher of the type having a rotating spraying means as distinguished from a motor driven impeller. The main motor of the dishwasher drives a pump 12a. This pump receives water or a washing solution from the sump 9, a fitting 2.7 on the sump being connected to a fitting 28 on the pump by means of a conduit 29 which, again, may be of flexible character. In the central portion of the sump there is a fitting 3% which is connected to the pump outlet fitting 31 by any suitable conduit means 32 as will be clear from FIG. 3. As therein shown the fitting 30 may consist of two parts bolted together about the periphery of an opening in the sump. It will be understood that gasket means are employed to effect a liquid tight connection between the fitting and the sump. There is a spray tube 33 extending across the inside of the vat above the sump. The spray tube has a central fitting 34 mounted rotatively on the fitting 30. Jet forming openings (not shown) will be provided in the spray tube 33 and, as well understood in this art, the axes of these openings may be so inclined that the reaction of the jets will cause a rotation of the spray tube.

A hollow fitting or downtake 35 is provided for the withdrawal of gases from the vat. This is shown as extending upwardly through the bottom of the sump, the upper end of the downtake being located above the level which will be reached by any accumulation of liquid in the sump. A splash guard 36 operates to prevent any falling portion of the liquid from entering the downtake. The downtake fitting 35 may, like the fitting 30, be formed in two flanged portions bolted together about the periphery of an opening in the floor of the sump.

The motor is again provided with a housing member 15, closed at one end by the pump 12a. At its opposite end the housing is closed by cup shaped member 37 having a tubular inlet portion 38 which is connected to the fitting 35 by any suitable conduit means 39.

The motor will be understood as having vanes such as the vanes 114- in FIG. 2, for the purpose of moving air through the housing 15. The air so moved Will issue from the housing through series of openings 16 adjacent that end of the housing which is closed by the pump, the said openings lying substantially opposite the vanes aforesaid. Gases from the interior of the vat will be withdrawn through the downtalre fitting 35 and will be caused to enter the motor housing 15 through the member 37. The dilution of the withdrawn gases may be accomplished by providing louvers 4b in the flat side of the member 37. Also a series of openings 41 may be made in the motor housing near the member 337 so that additional air will be drawn into the motor housing therethrough.

The motor may be mounted in the casing of the dishwasher in any way desired. It is possible to suspend the motor from the fittings 3t} and 35. The operation of the assembly, -it is believed, will be clear from the explanation given above in connection with FIGS. 1 and 2..

The same means as above described may be employed to permit the entry of air into the vat, as well as the described means for opening the space within the dishwasher casing below the vat to the outside atmosphere or for insuring the flow of outside air therethrough by convection or otherwise.

Adju-nctive means such as electrical heaters, solenoid valves, timers, means for withdrawing liquids from the vat and discharging them to a drain, and the like, have not been illustrated but are conventional.

Modifications may be made in the invention without departing from the spirit of it. The invention having been described in certain exemplary embodiments, what is claimed as new and desired to be secured by Letters Patent is:

1.. In a dishwashing machine of the type having sequential cycles of Washing, rinsing and drying, and having an outer casing, a vat within said casing and terminating downwardly in a sump, there being an electrical motor located said casing and below the said sump, the improvement which includes a ventilating system for the purpose described comprising a housing for said electrical motor, vanes on a moving part of said motor for producing a passage of gas through said housing, a gas downtake extending through a wall of said vat and terminating above the level of collected liquid in said sump, and a connection between said downtake and said motor housing so that operation of said motor will produce a continuous withdrawal of gas from said vat through said downtake, means for mixing with said gas a quantity of air outside said vat to minimize condensation of moisture in the gas withdrawn from said vat, and a means for admitting air to said vat to compensate for the gases withdrawn therefrom.

2. The structure claimed in claim 1 wherein said downtake is provided with 'a splash guard within said vat.

3. The structure claimed in claim 2 wherein the means for mixing air with the gases withdrawn from the vat comprise openings in the connection between the downtake and the motor housing.

4. The structure claimed in claim 3 wherein said motor housing has openings for the egress of gases withdrawn from said vat and for delivering said gases to the space in the said casing located below the sump.

5. The structure claimed in claim 4 wherein the said motor housing has additional openings so located as to produce a further dilution of the gases withdrawn from said -v-at with air surrounding said housing.

6. The structure claimed in claim 4 wherein the space within said casing and below the said sump is vented to the atmosphere surrounding said dishwasher.

7. The structure claimed in claim 6 wherein said motor drives an impeller within said vat.

8. The structure claimed in claim 6 wherein said motor drives an impeller within said vat, and wherein the said connection between the downtake and the motor housing includes a louvered conduit,

9. The structure claimed in claim 6 wherein said motor drives a pump, the pump having an intake means through said sump and an outlet means through said sump, and a spray tube means within said vat rotatabiy connected to said pump outlet means.

10. In an automatic dishwashing machine of the type having a plurality of sequential cycles including washing, rinsing and drying, and having an outer casing comprising a front wall, a rear wall, side walls, a top memher, and a bottom member, a tableware receiving vat within said casing, and access means in said casing to said vat, impeller means at the bottom of said vat, and an electric motor within said casing below said vat to drive said impeller, the improvement which includes a ventilating system comprising a housing for said electric motor, perforations in the sides of said housing, fan means in connection with said motor for drawing air upwardly through said housing, a horizontally oriented air duct within said casing, one end of said air duct being connected to the bottom of said motor housing, the other end of said air duct having an opening therein, a tube passing from said easing into said vat through said vat bottom, means for connecting said tube to said opening, at least one opening in said air duct for the passage of air from said easing into said duct, first vent means at the bottom of said casing for passage of air into said casing, second vent means in said casing for the passage of air firom said casing to the ambient atmosphere, and a third vent means for the passage of air from the ambient atmosphere into said vat.

11. The structure claimed in claim 10* wherein said access means in said casing to said vat comprises a door in said front well, said door hingedly aflixed to said casing and swingable downwardly and outwardly for access to said vat, said third vent means being located in part at least at the bottom of said door.

References Cited in the file of this patent UNITED STATES PATENTS 1,847,736 Ward Mar. 1, 1932 2,652,844 Van Hise Sept. 22, 1953 3,024,074 Jacobs et al Mar. 6, 1962 3,026,628 Berger et a1 Mar. 27, 1962 3,072,129 Seal Jan. 8, 1963 3,082,779 Jacobs Mar. 26, 1963 FOREIGN PATENTS 419,440 Great Britain Feb. 10, 1933 

1. IN A DISHWASHING MACHINE OF THE TYPE HAVING SEQUENTIAL CYCLES OF WASHING, RINSING AND DRYING, AND HAVING AN OUTER CASING, A VAT WITHIN SAID CASING AND TERMINATING DOWNWARDLY IN A SUMP, THERE BEING AN ELECTRICAL MOTOR LOCATED WITHIN SAID CASING AND BELOW THE SAID SUMP, THE IMPROVEMENT WHICH INCLUDES A VENTILATING SYSTEM FOR THE PURPOSE DESCRIBED COMPRISING A HOUSING FOR SAID ELECTRICAL MOTOR, VANES ON A MOVING PART OF SAID MOTOR FOR PRODUCING A PASSAGE OF GAS THROUGH SAID HOUSING, A GAS DOWNTAKE EXTENDING THROUGH A WALL OF SAID VAT AND TERMINATING ABOVE THE LEVEL OF COLLECTED LIQUID IN SAID SUMP, AND A CONNECTION BETWEEN SAID DOWNTAKE AND SAID MOTOR HOUSING SO THAT OPERATION OF SAID MOTOR WILL PRODUCE A CONTINUOUS WITHDRAWAL OF GAS FROM SAID VAT THROUGH SAID DOWNTAKE, MEANS FOR MIXING WITH SAID GAS A QUANTITY OF AIR OUTSIDE SAID VAT TO MINIMIZE CONDENSATION OF MOISTURE IN THE GAS WITHDRAWN FROM SAID VAT, AND A MEANS FOR ADMITTING AIR TO SAID VAT TO COMPENSATE FOR THE GASES WITHDRAWN THEREFROM. 